Yes, I would argue that Pound has succeeded in creating an exact visual image. Specifically, he achieves this with the line that reads, "Petals on a wet, black bough." This image is also a metaphor which compares the "faces in the crowd" to the petals of flowers that are growing from a wet, black bough of a tree. Thus, the flowers would likely be flesh tones of varied hue: browns and pinks and peaches and ivories. We can clearly see the image of softly colored petals attached to a dark tree limb that is, perhaps, slicked with rainwater. This is the exact visual image Pound creates.
In terms of the total poetic statement conveyed by this image, we must investigate the metaphor as well as the word choice of "apparition" in the first line. An apparition could be a ghost, an unexpected sight, or a sudden appearance. Perhaps the word choice refers to how fleeting this image of the faces is to the speaker. This unusual image seems to flash fleetingly before him. Flower petals also do not last long. They are fragile and soon give way to leaves and fruit. They are beautiful partially because they are fleeting. The poem seems to comment on the beauty of these human faces in the crowd, unusual because crowds are not typically thought of as beautiful. It also comments on the momentary quality of our impressions.